Video signal receivers such as direct broadcast satellite receivers and video cassette recorders (VCRs) provide video output signals as Radio Frequency (RF) modulated signals to a television receiver, for example. The carrier frequency selected for this RF modulation in the United States, for example, is usually the broadcast channel 3 or channel 4 television carrier frequency. Selection of one of these channels is typically accomplished by means of a user operated manual switch. This switch is usually located on the VCR or satellite receiver unit. The user of a satellite receiver, for example, is typically directed by an instruction manual to select the broadcast channel (3 or 4) that is not used in the user's local broadcast area. The user then selects that same channel on the television receiver to ensure that the television receiver is tuned to the same carrier frequency as the satellite receiver RF output.
A problem that may arise is incompatibility between a video receiver (e.g. satellite receiver or VCR) modulator output channel and the channel to which a television receiver, receiving the modulator output, is tuned. Such an incompatibility may occur if the user is unaware of the modulator channel setting of the video receiver, and sets the television receiver to a different channel. Then, the television receiver tuner will not be set to the same carrier frequency as the video receiver RF output signal. This situation may occur upon initial video receiver system set-up up. However, such an incompatibility can also occur if the user forgets which modulator channel he has selected, if he inadvertently changes the modulator channel, or the modulator channel is changed without his knowledge.